England fans react as their team scores during the FIFA Women's World Cup Australia & New Zealand 2023 Semi Final match between England and Australia, at Boxpark Wembley on August 16, 2023 in London, England. (Photo by Leon Neal/Getty Images)

Everyone wants to get something for nothing - whether it's a lucky upgrade that means you can turn left when you get on a plane instead or heading off into the economy seats, or even getting a few extra features thrown in for free when you buy a new car.

As some of the sharpest businesses around, no-one understands this quite as well as casinos and that's why they all have a system that they call comps. It's short for "complimentary offers" and these are special treats specially designed to reward you for your loyalty to the casino in question. They're basically bonuses.

A reveller holds a sign reading “2020BYE” as a small number of people begin celebrating New Year's Eve at the Sydney Harbour waterfront amidst tightened COVID-19 regulations in Sydney, Australia, December 31, 2020. (Photo by Loren Elliott/Reuters)

“Two Brothers”. We found about 20 lions eating a buffalo. When the male leaved the group we anticipated him to take photos. It is 8AM, light is perfect and the position too. The lion stops and looks down from the hill, another lion is coming up, it stiffens, I think that will be a fight, i'm tense, the camera is OK, the shots previously made perfect. The two meet, looking directly into their eyes, they sniff, rub against their heads, the tension drops, they start walking with the same step as when they were puppies, they are two brothers. Photo location: Masai Mara, Kenya. (Photo and caption by Massimo Mei/National Geographic Photo Contest)

A member of an Egungun masquerade group, his identity obscured under his ornate costume in Ouidah, Benin on March 13, 2019. The exclusively male practitioners, found across Yoruba culture, use dance and spinning in the belief that they will summon the spirits of ancestors. (Photo by Massimo Rumi/Barcroft Images)

A Tibetan girl is reflected in a mirror, as she gets ready for her performance during an event organised to mark the 88th birthday celebration of their spiritual leader, the Dalai Lama in Kathmandu, Nepal on July 6, 2023. (Photo by Navesh Chitrakar/Reuters)

Nepalese women farmers spray mud water at each other while planting rice in a paddy field during the National Paddy Day in the village of Jitpur in Kathmandu, Nepal, 30 June 2015. On this day, known as Asar Pandra, farmers begin the annual rice planting season and mark the day with various festivities such as preparing rice meals with muddy water, spreads mud among farmers. The Mud being a symbol for a prosperous season. The agricultural sector contributes about 60 per cent to Nepal's gross domestic product. (Photo by Narendra Shrestha/EPA)

Members of the Compagnie 1602 take part in a procession in Geneva December 14, 2014. The annual procession of the Fete de l'Escalade has been held since 1926 and commemorates local resistance to the December 11, 1602 surprise attack by the troops of the Duke of Savoy. A popular symbol of the resistance is the figure of Mere Royaume pouring hot soup from her caldron onto the soldiers. A chocolate replica of the cauldron is widely available during the three-day celebrations. This year marks also the 200-year anniversary of the entry of the Canton of Geneva in the Swiss Confederation. (Photo by Pierre Albouy/Reuters)